Possible breaking change beta2 -> RTM

Question

Hi All,

I've been upgrading my code from beta2 to RTM and my linq queries began to fail me.

All of them are with join keyword.

for example

 

var result = from a in context.Table1

join b in context.Table2 on a.Id equals b.Id

where a.Name.Equals("MyName")

select a;

 

this query (over SSCE I might add) is throwing an exception :

System.InvalidOperationException occurred
  Message="The query contains references to items defined on a different data context."
  Source="System.Data.Linq"
  StackTrace:
       at System.Data.Linq.SqlClient.QueryConverter.TranslateConstantTable(ITable table, SqlLink link)
       at System.Data.Linq.SqlClient.QueryConverter.CoerceToSequence(SqlNode node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitJoin(Expression outerSequence, Expression innerSequence, LambdaExpression outerKeySelector, LambdaExpression innerKeySelector, LambdaExpression resultSelector)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitWhere(Expression sequence, LambdaExpression predicate)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSelect(Expression sequence, LambdaExpression selector)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitAggregate(Expression sequence, LambdaExpression lambda, SqlNodeType aggType, Type returnType)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.ConvertOuter(Expression node)
       at System.Data.Linq.SqlClient.SqlProvider.BuildQuery(Expression query, SqlNodeAnnotations annotations)
       at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
       at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute(Expression expression)
       at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
       at Bar.foo(X x) in C:\myPath\myFile.cs:line 120
  InnerException:

 

Well this query worked well under beta2, and I don't know what I do wrong, the syntax seems correct, ot I missed some breaking change in that matter.

And Idea?

 

Thanks

Ariel

Answer 1

Try:

var result = from a in context.Table1

                 from b in context.Table2
                 where (a.Name.Equals("MyName") &&

                 (b.Id == a.Id))

                select a;

Bye.

Answer 2

Thanks, I tried that.

 

I guess the problem is really in the result list itself.

when I try something like result.Count<Table1Class>(), then the exception is thrown.

 

System.InvalidOperationException was unhandled
  Message="The query contains references to items defined on a different data context."
  Source="System.Data.Linq"
  StackTrace:
       at System.Data.Linq.SqlClient.QueryConverter.CheckContext(SqlExpression expr)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMemberAccess(MemberExpression ma)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSelectMany(Expression sequence, LambdaExpression colSelector, LambdaExpression resultSelector)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitWhere(Expression sequence, LambdaExpression predicate)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSelect(Expression sequence, LambdaExpression selector)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequence(Expression exp)
       at System.Data.Linq.SqlClient.QueryConverter.VisitDefaultIfEmpty(Expression sequence)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.Visit(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.VisitAggregate(Expression sequence, LambdaExpression lambda, SqlNodeType aggType, Type returnType)
       at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc)
       at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node)
       at System.Data.Linq.SqlClient.QueryConverter.ConvertOuter(Expression node)
       at System.Data.Linq.SqlClient.SqlProvider.BuildQuery(Expression query, SqlNodeAnnotations annotations)
       at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
       at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute(Expression expression)
       at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
  InnerException:

Still investigating.

Any help is welcomed.

 

Ariel

Answer 3

Ok guys,

I believe I found the answer.

The problem was that I was using a static DataContext.

So when queries began running cocurrent that when the exception occures.

 

So don't be lazy, create the Datacontext on every scope you have.

(From the MSDN : "A DataContext is lightweight and is not expensive to create. A typical LINQ to SQL application creates DataContext instances at method scope or as a member of short-lived classes that represent a logical set of related database operations").

 

That was a ***

Ariel